[PATCH v4 5/6] posix_cpu_timers_exit: wrong place to collect entropy

From: Nicolas Pitre
Date: Fri Nov 11 2016 - 00:11:00 EST


There is no logical relation between add_device_randomness() and
posix_cpu_timers_exit(). Let's move the former to where the later
is called. This way, when posix-cpu-timers.c is compiled out, there
is no need to worry about not losing a call to add_device_randomness().

Signed-off-by: Nicolas Pitre <nico@xxxxxxxxxx>
---
kernel/exit.c | 4 ++++
kernel/time/posix-cpu-timers.c | 4 ----
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/exit.c b/kernel/exit.c
index 9d68c45ebb..d16bcdd89d 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -54,6 +54,7 @@
#include <linux/writeback.h>
#include <linux/shm.h>
#include <linux/kcov.h>
+#include <linux/random.h>

#include <asm/uaccess.h>
#include <asm/unistd.h>
@@ -116,6 +117,9 @@ static void __exit_signal(struct task_struct *tsk)
sig->curr_target = next_thread(tsk);
}

+ add_device_randomness((const void*) &tsk->se.sum_exec_runtime,
+ sizeof(unsigned long long));
+
/*
* Accumulate here the counters for all threads as they die. We could
* skip the group leader because it is the last user of signal_struct,
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index 39008d7892..e582f20f47 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -9,7 +9,6 @@
#include <asm/uaccess.h>
#include <linux/kernel_stat.h>
#include <trace/events/timer.h>
-#include <linux/random.h>
#include <linux/tick.h>
#include <linux/workqueue.h>

@@ -447,10 +446,7 @@ static void cleanup_timers(struct list_head *head)
*/
void posix_cpu_timers_exit(struct task_struct *tsk)
{
- add_device_randomness((const void*) &tsk->se.sum_exec_runtime,
- sizeof(unsigned long long));
cleanup_timers(tsk->cpu_timers);
-
}
void posix_cpu_timers_exit_group(struct task_struct *tsk)
{
--
2.7.4